class Solution {
public:
    vector<int> intersection(vector<int>& nums1, vector<int>& nums2) {
        set<int> s1(nums1.begin(), nums1.end());
        set<int> s2(nums2.begin(), nums2.end());

        vector<int> v;
        auto it1 = s1.begin();
        auto it2 = s2.begin();
        while (it1 != s1.end() && it2 != s2.end())
        {
            if (*it1 < *it2)
            {
                ++it1;
            }
            else if (*it1 > *it2)
            {
                ++it2;
            }
            else
            {
                v.push_back(*it1);
                ++it1; ++it2;
            }

        }
    return v;
    }
};
